Why you should always encrypt your smartphone

Last week, California's Supreme Court reached a controversial 5-2 decision in People v. Diaz (PDF), holding that police officers may lawfully search mobile phones found on arrested individuals' persons without first obtaining a search warrant. The court reasoned that mobile phones, like cigarette packs and wallets, fall under the search incident to arrest exception to the Fourth Amendment to the Constitution.

California's opinion in Diaz is the latest of several recent court rulings upholding warrantless searches of mobile phones incident to arrest. While this precedent is troubling for civil liberties, it's not a death knell for mobile phone privacy. If you follow a few basic guidelines, you can protect your mobile device from unreasonable search and seizure, even in the event of arrest. In this article, we will discuss the rationale for allowing police to conduct warrantless searches of arrestees, your right to remain silent during police interrogation, and the state of mobile phone security.